Dyed lubricating oil



Patented Feb. 23, 1937 UNITED STATES PATENT OFFICE 'DYED LUBRICATING OIL No Drawing. Application November 16, 1931, Serial No. 575,461

1 Claim. (01. 196 151) This invention relates to a dyed lubricating oil. The dye is obtained from tars produced in the cracking of petroleum products, but these are not used as such as additions to oils, in our product. The invention will be fully understood from the following description.

In the co-pending application Ser. No. 572,059 filed October 30, 1931 by Stewart C. Fulton a process has been described for obtaining resins from heavy petroleum products, especially cracked tars of petroleum origin. Briefly this process consists of removing most of the oily constituents from the cracked tar by distillation preferably under vacuum and agitating or digesting the residual product with a light petroleum hydrocarbon solvent, such as naphtha, to dissolve the resins therefrom and to obtain asphaltenes as residual product. The naphtha solution is then acid treated, neutralized either with finely divided clay or by washing, and distilled to remove the solvent. The residual product is a resin having the following properties;

Softening point Light naphtha, gasoline, etc.

Linseed oil smuble China wood oil Esters, such as amyl acetate g entzol a er Ipsohlble {Lower alcohols Acetone Solubility We have discovered that resins obtained from cracked tars of petroleum origin by separating the oily products and asphaltenes from the resin, are good materials for dyeing lubricating oils. Such resins may be prepared by the above described method, or by other methods also. The resin may be added either to a lubricating oil distillate or to a cylinder oil when a darker color is desired, or it may be added to the so-called pale oils to give them a desired shade of color. In all cases the cast of the oil dyed by the addition of such resins is greatly improved inasmuch as these resins impart a desirable olive green cast to the oils dyed therewith.

The resin may be dissolved in a lubricating oil by agitation, with slight warming in case of a viscous oil. It is preferable to prepare first an intermediate solution by dissolving say 10% by weight of resin in a certain portion of the oil and use this intermediate solution for dyeing large quantities. The amount of resin in the final dyed lubricating oil product is usually less than about 1%. Solutions of the resin in other 501- vents may of course be used. For example, a concentrate of the resin in the solvent employed in the resin-separating process, such as kerosene, may be added to the lubricating oil. The amount of solvent required to be used is too small to affect the properties of the oil.

The following example will illustrate our process and the products obtained. A pale lubricating oil prepared by vacuum pipe still operation from Colombia crude was divided into two lots and dyed with a resin obtained from cracking coil tar by first preparing an intermediate solution and then adding varying amounts of this intermediate solution to the two lots of lubricating oil. The following table will show the inspection of the original product and the dyed products:

Original Dyed oil Dyed oil oil No. 1 No. 2

Oil dye, by weight 0. 0 0. 2 0. 7 Gravity, A I 23. 1 23. 0 22. 9 Flash F 420 420 420 Viscosity F. (Saybolt) 520 524 635 Viscosity 210F. (Saybolt) 57. 4 57. 4 57. 6 Viscosity index 54 55 51 Color (Robinson) 0% 5? i???"'it'fiFEd'ifdi" i 'y i o ora er ea mg 5. S. E. (steam emulsion number as 4 2 defined in A. S. T. M. report of Committee D-2, 1932) 231 Comadson carbon. 0.02 0. 08 0.22 Cast Poor Good Good The present invention permits of imparting the desired cast or fluorescence to the lubricating oil and to eirect other improvements. Thus we have observed that the pour point of certain lubricating oils, such as for example thepour of light and medium hydrogenated oils, is lowered by the incorporation of resins prepared from cracked tars of petroleum origin.

Our invention may be used with special advantage to the preparation of lubrication oils known in the trade under the name of red oils. A great many users of lubricating oils demand red oils in preference to the lighter colored pale oils. Many red oils on the market are blends of pale oils with suflicient viscous red oil (bright stock) to yield the desired color. The sought for color of red oils can be obtained by the addition of our dye concentrate which does not cause the impairment in oil quality attendant to the use of bright stock blends. The following exthe addition of 5% bright stock and the other one by the addition of 0.08% resin:

- Pale oil Pale oil+5% Pale 01] bright stock *ggg Gravity A. P. I 27 1 26 9 27. 1 Viscosity Saybolt at 210 F 53 2 54 63. 4 Color Tag-Robinson"..- 14 9 9 Carbon residue O 07 0.01 Pour F 0 0 15 It is seen that the red oil prepared with the resin is of a superior quality in comparison to the red oil of the same color prepared by the addition of bright stock as proved by the Conradson carbon test. The pour of the red oil prepared with the resin was also lower than that of the original pale oil or that of the red oil prepared by the addition of bright stock. The steam emulsion number is also better when the red oil is prepared with resin.

The amount of resin to be added to the pale oil depends on the desired color of the red oil. Usually this amount is below 1% but in some cases it may be higher, 25% or even higher.

Our invention is not to be limited by the particulars given by way of illustration but merely by the following claim in which it is our intention to claim all novelty inherent in the invention.

We claim:

A lubricating oil containing a pour point depressant and bloom agent prepared by distilling cracked petroleum residue to remove the oily constituents therefrom, extracting the distilled residue with a solvent in which asphaltenes are substantially insoluble, subjecting the extract containing the solvent to acid treatment, neutralizing the acid treated solvent extract and distilling off the solvent to form the pour point depressant and bloom agent.

CARL WINNING. STEWART C. FULTON. 

